McCain said he would "confront" the massive federal debt and would balance the annual federal budget by the end of his term in office, without specifying whether he meant in four years or perhaps eight years should he be elected twice.

McCain has long promised to balance the budget but this was the first time he renewed the pledge since the enactment of a $700 billion bailout this month of troubled financial institutions which could complicate such an effort. Many presidential candidates have promised to balance the budget but the last to do so was Democrat Bill Clinton, who had four budget surpluses beginning in 1998. That was the first surplus since 1969 and the first string of surpluses since one that ended in 1930.

In delivering this pledge, McCain committed a verbal bobble, which quickly made its way onto YouTube.

"Across this country, this is the agenda I have set before my fellow prisoners and the same standards of clarity and candor must now be applied to my opponent," said McCain, who often speaks about his time as a prisoner of war in Vietnam. His prepared remarks said "fellow citizens," not "fellow prisoners."

Speaking to a rowdy crowd of supporters in this eastern Pennsylvania town, McCain and his running mate, Sarah Palin, both challenged Democrat Barack Obama's campaign claims. Dismissing Obama as just "a guy who's just tried to talk his way into the White House," vice presidential candidate Palin said the Democrats' ideas are stale and dangerous.

"He's not willing to drill for energy, but he's sure willing to drill for votes," Palin said, eliciting cheers of "Drill, baby, drill" from the crowd, which often interrupted the candidates during their joint appearance.

McCain's remarks about Obama were interrupted with shouts of "socialist," "terrorist" and "liar." At another time, a man in the bleaches shouted "No more ACORN," referring to a group that registers poor voters.

"We've all heard what he's said. But it's less clear what he's done, or what he will do," McCain said.

The crowd replied with chants, "Nobama."

Similarly, Palin said there were too many questions about Obama's past: "John McCain didn't just come out of nowhere. The American people know John McCain."

Advisers say the Republican ticket will continue this forceful tone as the campaign enters its final months. Obama leads in national and state polls; McCain is looking for a way to change that.

McCain is trying to move Pennsylvania and its 21 electoral votes out of the Democratic column; President Bush lost the state to Democrats in 2000 and 2004. Obama has one extra advantage this year: Democratic voter registration surged by 13 percent while Republican ranks shrunk by 1 percent as a record 8.6 million Pennsylvanians registered to vote in this presidential election.

Statewide, Democrats outnumber Republicans by nearly 1,170,000 voters, almost twice the edge they had a year ago.

"Which candidate's experience, in government and in life, makes him a more reliable leader for our country and commander in chief for our troops?" McCain said. "In short, who is ready to lead?"

McCain's speech centered on policies that would help the working-class voters in this region where the race is close. Obama lost Pennsylvania's Democratic primary to Sen. Hillary Rodham Clinton and has struggled to connect with the white, working-class voters he once said cling to guns and religion in times of economic uncertainty.

"What Sen. Obama says today and what he has done in the past are often two different things," McCain said.

"Who is the real Sen. Obama?" McCain said, repeating a line he debuted on Monday in New Mexico, another state he needs to win White House. "Is he the candidate who promises to cut middle-class taxes, or the politician who voted to raise middle-class taxes?"

Online Public Information File

Viewers with disabilities can get assistance accessing this station's FCC Public Inspection File by contacting the station with the information listed below. Questions or concerns relating to the accessibility of the FCC's online public file system should be directed to the FCC at 888-225-5322, 888-835-5322 (TTY), or fccinfo@fcc.gov.